The Refill Station allows the player to interact with a pipe system. The player can add iridium by left clicking. The player can also take Iridium by pressing "e". The refill station although might seem useful, is usually useless in the early, mid, and end game. This is due to the fact that the spawn point, and the standard tank have a refill console (Refill consoles act exactly the same as refill stations) included in it. In the mid and end game, the distributor automatically fills the player's tank. Usually people use it for convenience like if there is no refill console or distributor nearby.
However, there are a few situations when it is useful. One is when constructing a skybase, refilling stations can be used to decrease the distance a player has to climb down after constructing each ladder. Another is for hijacking enemy bases. When destroying a pipe with a laser drill, you can connect a refill station to it and manually remove iridium from the enemy.
For its small size it takes the unupgraded portafab a long time to destroy it. This may be changed in the future though.